Efectividad de un programa de entrenamiento neuromuscular de 6 semanas de duración aplicado en el tobillo en la realización del Star Excursion Balance Test en jugadores de baloncesto

Introducción: La mayoría de lesiones que se registran en la práctica del baloncesto se localizan en la extremidad inferior, especialmente en el tobillo, y son la principal causa de ausencia en las sesiones de entrenamiento. Estas lesiones pueden repercutir en un aumento del riesgo de recidiva de la lesión. Objetivos: Determinar si un programa de entrenamiento propioceptivo, confeccionado en base a ejercicios propios del baloncesto, podría provocar un cambio en la estabilidad dinámica de un grupo de jugadores de baloncesto, usando el Star Excursion Balance Test (SEBT) para su valoración. Determinar el número de repeticiones necesarias para la correcta interpretación del SEBT. Material y métodos: Estudio experimental. Se seleccionaron 17 jugadores de baloncesto (8 grupo experimental [GE] y 9 grupo control [GC]); GE = 15,12 ± 0,83 años; GC = 14,67 ± 1,0 años. El GE realizó un programa de entrenamiento específico durante el calentamiento, mientras que el GC completó su rutina habitual. El SEBT se realizó antes y después de 6 semanas de desarrollo del programa. Para el análisis estadístico se utilizó un MANOVA 2 × 2, por grupo y tiempo. Resultados: Solo las mediciones para la dirección posterolateral fueron significativas en los 2 grupos (GC: MDIF = 15,5; p = 0,002; IC 95%: 6,83-24,17 cm; GE: MDIF = 12,063; p = 0,014; IC 95%: 2,87-21,26 cm). No existieron diferencias significativas entre los grupos para las demás direcciones. Conclusiones: Una repetición del test fue suficiente. La realización de un programa específico de propiocepción para jugadores sanos de baloncesto no obtuvo mejoras en el equilibrio

Efectivitat d’un programa d’entrenament neuromuscular del turmell aplicant l’Star Excursion Balance Test a jugadors de bàsquet durant 6 setmanes

Introducció: La majoria de lesions que es registren en la pràctica del bàsquet es localitzen a l’extremitat inferior, especialment al turmell, i són la causa principal d’absència a les sessions d’entrenament. Aquestes lesions poden repercutir en un augment del risc de recidiva de la lesió. Objectius: Determinar si un programa d’entrenament propioceptiu, confeccionat a base d’exercicis propis del bàsquet, podria provocar un canvi de l’estabilitat dinàmica d’un grup de jugadors de bàsquet, emprant com a instrument de valoració l’Star Excursion Balance Test (SEBT). Determinar el nombre de repeticions que calen per interpretar correctament l’SEBT. Material i mètodes: Estudi experimental. Es seleccionaren 17 jugadors de bàsquet (8 del grup experimental [GE] i 9 del grup control [GC]); GE = 15,12 ± 0,83 anys; GC = 14,67 ± 1,0 anys. El GE realitzà un programa d’entrenament específic durant l’escalfament, mentre que el GC seguia la seva rutina habitual. L’SEBT es realitzà abans i després de 6 setmanes de desenvolupar el programa. Per a l’anàlisi estadística s’emprà un MANOVA 2 × 2, per grup i temps. Resultats: Únicament foren significatius els mesuraments de la direcció posterolateral en els 2 grups (GC: MDIF = 15,5; p = 0,002; IC 95%: 6,8324,17 cm; GE: MDIF = 12,063; p = 0,014; IC 95%: 2,87-21,26 cm). No hi hagué diferències significatives entre els grups en les altres direccions. Conclusions: Només calgué una repetició del test. La realització d’un programa específic de propiocepció per a jugadors de bàsquet sans no obtingué millores de l’equilibri

Effects of a 6-week neuromuscular ankle training program on the Star Excursion Balance Test for basketball players

Background: The largest percentage of injuries in basketball affect the lower limbs, specially the ankle joint, and this is the major cause of missed days of training during a season. Moreover, ankle injuries can increase the risk factor of recurrent injuries. Objectives: To determine whether a training program, based on specific ankle exercises for basketball, causes a change in the dynamic stability of a healthy group of basketball players, using the Star Excursion Balance Test (SEBT). Also, to determine the ideal number of repetitions to obtain a reliable measure of the test. Materials and methods: Experimental study. Seventeen uninjured basketball players participated (8 experimental [EG], 9 control [CG]) (EG = 15.12 yrs ± 0.83 yrs; CG = 14.67 yrs ± 1.0 yrs).The EG performed the training program during the warm-up, and the CG completed the regular warm-up. The SEBT was performed before and after the 6-week training program. In statistical analysis MANOVA 2 * 2 was used per group and time. Results: Only the measurements for the Posterior-Lateral direction were significant, namely in 2 groups (CG: Mdif = 15.5, P = .002 [95% CI: 6.83-24.17 cm]; EG: Mdif = 12.063, P = .014 [95% CI: 2.87-21.26 cm]). There were no differences in the SEBT between groups after the training protocol. Conclusions: One attempt seems to be sufficient for the completion of the test. The completion of a specific training program for healthy basketball players does not demonstrate improvements in the balance

3D measurements in conventional X-ray imaging with RGB-D sensors

[EN] A method for deriving 3D internal information in conventional X-ray settings is presented. It is based on the combination of a pair of radiographs from a patient and it avoids the use of X-ray-opaque fiducials and external reference structures. To achieve this goal, we augment an ordinary X-ray device with a consumer RGB-D camera. The patient' s rotation around the craniocaudal axis is tracked relative to this camera thanks to the depth information provided and the application of a modern surface-mapping algorithm. The measured spatial information is then translated to the reference frame of the X-ray imaging system. By using the intrinsic parameters of the diagnostic equipment, epipolar geometry, and X-ray images of the patient at different angles, 3D internal positions can be obtained. Both the RGB-D and Xray instruments are first geometrically calibrated to find their joint spatial transformation. The proposed method is applied to three rotating phantoms. The first two consist of an anthropomorphic head and a torso, which are filled with spherical lead bearings at precise locations. The third one is made of simple foam and has metal needles of several known lengths embedded in it. The results show that it is possible to resolve anatomical positions and lengths with a millimetric level of precision. With the proposed approach, internal 3D reconstructed coordinates and distances can be provided to the physician. It also contributes to reducing the invasiveness of ordinary X-ray environments and can replace other types of clinical explorations that are mainly aimed at measuring or geometrically relating elements that are present inside the patient's body.(C) 2017 IPEM. Published by Elsevier Ltd. All rights reserved.The authors would like to thank the Radiation Oncology Department of the Physics Section at La Fe Hospital for the anthropomorphic phantom used in this work and Jose Manuel Monserrate (Instituto de Física Corpuscular) for his contribution in the development of the calibration frame shown in Fig. 3. This research has the support of Information Storage S.L., University of Valencia (grant CPI-15-170), CSD-2007-00042 Con solider Ingenio CPAN (grant CPAN-13TR01), IFIC (Severo Ochoa Centre of Excellence SEV20140398) as well as the support of the Spanish Ministry of Industry, Energy, and Tourism (grant TSI1001012013019).Albiol Colomer, F.; Corbi, A.; Albiol Colomer, A. (2017). 3D measurements in conventional X-ray imaging with RGB-D sensors. Medical Engineering & Physics. 42:73-79. https://doi.org/10.1016/j.medengphy.2017.01.024S73794

Evaluation of modern camera calibration techniques for conventional diagnostic X-ray imaging settings

[EN] We explore three different alternatives for obtaining intrinsic and extrinsic parameters in conventional diagnostic X-ray frameworks: the direct linear transform (DLT), the Zhang method, and the Tsai approach. We analyze and describe the computational, operational, and mathematical background differences for these algorithms when they are applied to ordinary radiograph acquisition. For our study, we developed an initial 3D calibration frame with tin cross-shaped fiducials at specific locations. The three studied methods enable the derivation of projection matrices from 3D to 2D point correlations. We propose a set of metrics to compare the efficiency of each technique. One of these metrics consists of the calculation of the detector pixel density, which can be also included as part of the quality control sequence in general X-ray settings. The results show a clear superiority of the DLT approach, both in accuracy and operational suitability. We paid special attention to the Zhang calibration method. Although this technique has been extensively implemented in the field of computer vision, it has rarely been tested in depth in common radiograph production scenarios. Zhang¿s approach can operate on much simpler and more affordable 2D calibration frames, which were also tested in our research. We experimentally confirm that even three or four plane-image correspondences achieve accurate focal lengths.This work was carried out with the support of Information Storage S. L., University of Valencia (Grant #CPI-15170), CSD2007-00042 Consolider Ingenio CPAN (Grant #CPAN13TR01), Spanish Ministry of Industry, Energy and Tourism (Grant #TSI-100101-2013-019), IFIC (Severo Ochoa Centre of Excellence #SEV-2014-0398), and Dr. Bellot's medical clinic.Albiol Colomer, F.; Corbi, A.; Albiol Colomer, A. (2017). Evaluation of modern camera calibration techniques for conventional diagnostic X-ray imaging settings. Radiological Physics and Technology. 10(1):68-81. https://doi.org/10.1007/s12194-016-0369-yS6881101Selby BP, Sakas G, Groch W-D, Stilla U. Patient positioning with X-ray detector self-calibration for image guided therapy. Aust Phys Eng Sci Med. 2011;34:391–400.Markelj P, Likar B. Registration of 3D and 2D medical images. PhD Thesis, University of Ljubljana; 2010.Miller T, Quintana E. Stereo X-ray system calibration for three-dimensional measurements. Springer, 2014. pp. 201–207.Rougé A, Picard C, Ponchut C, Trousset Y. Geometrical calibration of X-ray imaging chains for three-dimensional reconstruction. Comput Med Imaging Graph. 1993; 295–300.Trucco E, Verri A. Introductory techniques for 3-D computer vision. Prentice Hall Englewood Cliffs, 1998.Moura DC, Barbosa JG, Reis AM, Tavares JMRS. A flexible approach for the calibration of biplanar radiography of the spine on conventional radiological systems. Comput Model Eng Sci. 2010; 115–137.Schumann S, Thelen B, Ballestra S, Nolte L-P, Buchler P, Zheng G. X-ray image calibration and its application to clinical orthopedics. Med Eng Phys. 2014;36:968–74.Selby B, Sakas G, Walter S, Stilla U. Geometry calibration for X-ray equipment in radiation treatment devices. 2007. pp. 968–974.de Moura DC, Barbosa JMG, da Silva Tavares JMR, Reis A. Calibration of bi-planar radiography with minimal phantoms. In: Symposium on Informatics Engineering. 2008. pp. 1–10.Medioni G, Kang SB. Emerging topics in computer vision. Prentice Hall. 2004.Bushong S. Radiologic science for technologists: physics, biology, and protection. Elsevier. 2012.Rowlands JA. The physics of computed radiography. Phys Med Biol. 2002;47:123–66.Dobbins JT, Ergun DL, Rutz L, Hinshaw DA, Blume H, Clark DC. DQE(f) of four generations of computed radiography acquisition devices. Med Phys. 1995;22:1581–93.Hartley R. Self-calibration from multiple views with a rotating camera. In: European Conference on Computer Vision. 1994. pp. 471–478.Tsai R. A versatile camera calibration technique for high accuracy 3D machine vision metrology using off-the-shelf TV cameras and lenses. IEEE J Robot Autom. 1985;3(4):323–44.Hartley R, Zisserman A. Multiple view geometry in computer vision. Cambridge University Press. 2004.Zhang Z. A flexible new technique for camera calibration. IEEE Trans Pattern Anal Mach Intell. 2000;22:1330–4.Remondino F, Fraser C. Digital camera calibration methods: considerations and comparisons. Symposium Image Eng Vis Metrol. 2006;36:266–72.Zollner H, Sablatnig R. Comparison of methods for geometric camera calibration using planar calibration targets. In: Digital Imaging in Media and Education. 2004. pp. 237–244

Geometrical Calibration of X-Ray Imaging With RGB Cameras for 3D Reconstruction

(c) 2016 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other users, including reprinting/ republishing this material for advertising or promotional purposes, creating new collective works for resale or redistribution to servers or lists, or reuse of any copyrighted components of this work in other works.We present a methodology to recover the geometrical calibration of conventional X-ray settings with the help of an ordinary video camera and visible fiducials that are present in the scene. After calibration, equivalent points of interest can be easily identifiable with the help of the epipolar geometry. The same procedure also allows the measurement of real anatomic lengths and angles and obtains accurate 3D locations from image points. Our approach completely eliminates the need for X-ray-opaque reference marks (and necessary supporting frames) which can sometimes be invasive for the patient, occlude the radiographic picture, and end up projected outside the imaging sensor area in oblique protocols. Two possible frameworks are envisioned: a spatially shifting X-ray anode around the patient/object and a moving patient that moves/rotates while the imaging system remains fixed. As a proof of concept, experiences with a device under test (DUT), an anthropomorphic phantom and a real brachytherapy session have been carried out. The results show that it is possible to identify common points with a proper level of accuracy and retrieve three-dimensional locations, lengths and shapes with a millimetric level of precision. The presented approach is simple and compatible with both current and legacy widespread diagnostic X-ray imaging deployments and it can represent a good and inexpensive alternative to other radiological modalities like CT.This work was carried out with the support of Information Storage S.L., University of Valencia (grant #CPI-15-170), CSD2007-00042 Consolider Ingenio CPAN (grant #CPAN13-TR01) as well as with the support of the Spanish Ministry of Industry, Energy and Tourism (Grant TSI-100101-2013-019).Albiol Colomer, F.; Corbi, A.; Albiol Colomer, A. (2016). Geometrical Calibration of X-Ray Imaging With RGB Cameras for 3D Reconstruction. IEEE Transactions on Medical Imaging. 35(8):1952-1961. https://doi.org/10.1109/TMI.2016.2540929S1952196135

Power Assessment in Road Cycling: A Narrative Review

Nowadays, the evaluation of physiological characteristics and training load quantification in road cycling is frequently performed through power meter data analyses, but the scientific evidence behind this tool is scarce and often contradictory. The aim of this paper is to review the literature related to power profiling, functional threshold testing, and performance assessment based on power meter data. A literature search was conducted following preferred reporting items for review statement (PRISMA) on the topic of {"cyclist" OR "cycling" AND "functional threshold" OR "power meter"}. The reviewed evidence provided important insights regarding power meter-based training: (a) functional threshold testing is closely related to laboratory markers of steady state; (b) the 20-min protocol represents the most researched option for functional threshold testing, although shorter durations may be used if verified on an individual basis; (c) power profiling obtained through the recovery of recorded power outputs allows the categorization and assessment of the cyclist''s fitness level; and (d) power meters represent an alternative to laboratory tests for the assessment of the relationship between power output and cadence. This review elucidates the increasing amount of studies related to power profiling, functional threshold testing, and performance assessment based on power meter data, highlighting the opportunity for the expanding knowledge that power meters have brought in the road cycling field

The relationship between maximum isometric strength and ball velocity in the tennis serve

The aims of this study were to analyze the relationship between maximum isometric strength levels in different upper and lower limb joints and serve velocity in competitive tennis players as well as to develop a prediction model based on this information. Twelve male competitive tennis players (mean ± SD; age: 1 7.2 ± 1.0 years; body height: 180.1 ± 6.2 cm; body mass: 71.9 ± 5.6 kg) were tested using maximum isometric strength levels (i.e., wrist, elbow and shoulder flexion and extension; leg and back extension; shoulder external and internal rotation). Serve velocity was measured using a radar gun. Results showed a strong positive relationship between serve velocity and shoulder internal rotation (r = 0.67; p < 0.05). Low to moderate correlations were also found between serve velocity and wrist, elbow and shoulder flexion – extension, leg and back extension and shoulder external rotation (r = 0.36 – 0.53; p = 0.377 – 0.054). Bivariate and multivariate models for predicting serve velocity were developed, with shoulder flexion and internal rotation explaining 55% of the variance in serve velocity (r = 0.74; p < 0.001). The maximum isometric strength level in shoulder internal rotation was strongly related to serve velocity, and a large part of the variability in serve velocity was explained by the maximum isometric strength levels in shoulder internal rotation and shoulder flexion.peerReviewe

Effects of different maturity status on change of direction performance of youth tennis players

[EN] The aim of this study was to examine the maturational status (i.e., peak height velocity [PHV]) differences in neuromuscular performance (i.e., vertical jump, linear sprint, change of direction (COD) using different tests, and change of direction deficit [CODD]) of young tennis players. One hundred and two tennis players (70 boys and 52 girls; age 13.9 ± 2.0 years, body mass 53.3 ± 12.7 kg, height 163.1 ± 11.9 cm) participated in the study and were divided into Pre-PHV (n = 26), Circa-PHV (n = 33) and Post-PHV (n = 43) groups. Testing included speed (5, 10, and 20 m), COD tests (i.e., modified 5-0-5, pro-agility and hexagon), and bilateral/unilateral countermovement jump (CMJ). Pre- and Circa-PHV players presented lower levels of performance in jumping ability (i.e., both bilateral and unilateral CMJs; P < 0.001; ES: 0.85 to 0.98), linear sprints (5 to 20 m; P < 0.05 to < 0.001; ES: 0.67 to 1.19) and COD ability tests (modified 5-0-5 test, proagility and hexagon) compared to the Post-PHV players. Moreover, Pre-PHV players presented lower CODD% (p < 0.05; ES: 0.68–0.72) than Post-PHV for both forehand and backhand sides, and Circa-PHV showed lower values in the CODD of the rolling situation to the forehand side (p < 0.05; ES: 0.58). Among the COD tests, the pro-agility test seems to be a simple, easy-to-implement and reliable test, which can provide interesting information about the COD with higher entry speeds. Moreover, specific training strategies related to the PHV and focused not only on the neuromuscular training and COD workouts, but also on maximizing motor skill proficiency, should be recommended.S

Validation of the Bar-On EQ-i: YV (S) Inventory in Its Spanish Version: Gender-Based Invariance Analysis

The purpose of this work is to verify the factorial structure and analyze the reliability of the Emotional Quotient Inventory (EQ-i): Youth Version (YV) (S) by evaluating emotional intelligence in a more extensive sample of Spanish adolescents than has been used to date, since this inventory has been employed in various studies but with a very limited number of participants. For this study, 5292 adolescents from all over Spain participated—male (51.2%) and female (48.8%) secondary education students between 11 and 19 years old, with an average age of 14.33. Data analysis included a Confirmatory Factor Analysis (CFA), reliability analysis, and model invariance as a function of gender. The CFA confirms that the data empirically support the theoretical model and that the goodness-of-fit indexes are adequate. The reliability analysis of the inventory presents a Cronbach’s alpha coefficient for the total scale of 0.76, and reliability indexes for each of the factors range between 0.63 and 0.80. The findings show that the model indicates invariance related to gender.This research was funded by the Spanish Ministry of Economy and Competitiveness (grant number EDU2015-64562-R)